Cartilage imaging

Excerpt

The imaging of cartilage in children differs from that in adults because physeal and epiphyseal cartilage are structurally and biochemically different than articular cartilage. Articular cartilage is primarily composed of a matrix of collagen and proteoglycans with few cells (less than 2% by volume). Physeal cartilage, by comparison, is very cellular. In the hypertrophic zone of the physis, 75% of the volume is made up by cells [1]. Epiphyseal cartilage is also vascular, whereas articular cartilage is avascular. Physeal cartilage is vascular during the first 18 months of life and then it becomes avascular. There are some similarities as well: the matrix of all the forms of cartilage (articular, epiphyseal and physeal) is composed of a matrix of collagen and glycosaminoglycans (GAGs). Collagen provides tensile strength, stability and resistance to shear forces. GAGs have a water absorbent capacity (much like a sponge) that allows cartilage to resist compression and to return to its shape once the pressure is released. …